This invention relates to utility blades and in particular to a conventional type of utility blade designed to be held by various types of handles.
One type of well known utility implement or knife comprises a generally trapezoidal blade, with its cutting edge on its longest side, and a handle which holds the blade and exposes only a portion of the cutting edge for use. This type of blade is marketed by several companies, including Stanley and Hyde, and is commonly used by retail merchants to open cardboard boxes. For example, during the stocking of grocery store shelves, it is most efficient if the entire top and a portion of the side walls of the cardboard box can be removed so that the packages inside can be quickly taken out and shelved. Because approximately half the cutting edge of the trapezoidal blade is exposed beyond the handle of the conventional utility knife, a substantial portion of the cutting edge often extends into the interior of the box and can result in cutting the packages inside the box. For example, cereal packages are packed inside large cardboard boxes such that the walls of the cereal packages are in direct contact with the inside wall of the cardboard box.
Various attempts have been made by manufacturers of utility blade handles to provide a knife which cuts the cardboard box without damaging the contents. For example, U.S. Pat. No. 3,092,903 to Bockhold and U.S. Pat. No. 4,167,810 to Gilbert both disclose modified handles for holding conventional utility blades such that the blades cut the carton without damaging the contents.